1. Field of the Invention
This invention relates to biologically active compounds and in particular to certain novel compounds exhibiting activity at thomboxane receptor sites.
2. Description of the Prior Art
Thromboxane A.sub.2 (TXA.sub.2), which is derived from arachidonic acid via prostaglandin H.sub.2 (PGH.sub.2), is implicated in several potentially noxious actions on various body systems, including platelet aggregation, bronchoconstriction and pulmonary and systemic vasoconstriction. Thus TXA.sub.2 may be involved in the normal sealing of blood vessels following injury but in addition may contribute to pathological intravascular clotting or thrombosis. Moreover, the constrictor actions of TXA.sub.2 on bronchiolar, pulmonary vascular and systemic vascular smooth muscle may be important in the development of several anaphylactic conditions including bronchial asthma. There is also some evidence to implicate PGH.sub.2 and TXA.sub.2 in the genesis of inflammation.